#include <iostream>
#include <cmath>

int main() {
    using namespace std;

    double area;
    cout << "Enter the floor area, in square feet of your home: ";
    cin >> area;

    double side;
    side = sqrt(area);  // 库函数sqrt, 求平方根
    cout << "That's the equivalent of a square " << side << " feet to the side." << endl;
    cout << "How fascinating!" << endl;
}